1. Field of the Invention
The present invention generally relates to computer systems employing multiple processors and multiple computer memories with means for interconnecting the processors and memories. More particularly, the present invention relates to an apparatus and method for interconnecting multiple digital computers with multiple computer memories according to a hierarchy of priorities among said computers.
2. Description of the Related Art
Modern computer systems typically employ a plurality of digital computers which execute a software operating system for distributing program tasks among the digital computers. One means for communication between the various computers is the allocation of a common memory area accessible by two or more of the computers. Also, task sharing between the computers requires that the same memory file be processed by two or more computers. This memory file must therefore lie in a common area of memory to permit access by several computers.
Many modern computer systems employ a modular architecture. Standard modules such as processor units, memory units, and input/output units are connected as required to provide the computing capability required for a given system. A wide variety of computer systems may thus be constructed using these standard modules. Also, a particular computer system employing a modular architecture can grow in an orderly fashion by the addition of standard modules as required when increased processing capability is needed.
Several types of computer architecture have been employed in modern computer systems, as are more particularly described later herein. Examples of these configurations are: pipeline, global memory, local/global memory and mesh. Each type of configuration has its particular advantages and disadvantages for certain types of information processing. In general, system building blocks or modules suitable for implementing one type of configuration are frequently not suitable for implementing another. Ideal computer system modules are equally adaptable to the implementation of several types of computer architecture.